Self-reading grade target



FebQZB, 1965 E. w COTTON 3,170,239

SELF-READING GRADE TARGET Filed Jan. :21, 1965 2 S ets-S eet 1 SlGHTlNG U P GEADE f GRADE SIGHTING DOWN- GRADE FIG. '1.

EDGAR W. COTTON INVENTOR.

ATTORNEYS.

Feb. 23, 1965 v E. w COTTON ssmmmomc GRADE TARGET 2 Sheets-Sheet --2 EDGAQ W. COTTON INVENTOR.

Filed Jan. 21, 1963 M .B N a W w Q 6. cm @5 6 H Q SELF-READING GRADE TARGET Edgar W. Cotton, 2562 Santa Ana St., Costa Mesa, Calif.

Filed Jan. 21, 1963, Ser. No. 252,192

-2 Claims. (Cl. 3370) 1 Thisiinvention relates to a jmethod and apparatus for ditchingwherein the'grade in'thebottom of the ditch must be maintained at a predetermined slope;

Explanatory of thepresent-fzinvention, many localities require that the slope of a. sewer. connection leading from a residence or other building we connection to a sewer main be maintained at a predetermined slope or fall."

A typical slope or fallis A" per foot, although this maysituations where the top surface of the ground at some below the bottom of the proposed localities is, actually ditch. v

The common practice heretofore has beento set up a builders level on theline of the proposed ditch which builders level has a telescope equipped withvertical and horizontal cross-hairs. ,By temporarily positioning a target pole at various intervals along the line of the proposed ditch which target pole is located by sighting it through the telescope against the vertical cross-hair, a seriesyof stakes can be driven locating the course of the proposed ditch. Then, by measuring carefully the hori zontal distances of. the stakes from the sewer connection and making computations or resorting to tables the depth to which'the ditch must be dug at each stake can-be determined in order to maintain the required slope or fall. When the'terrain is decidedly uneven it is difiicult to accurately measure the horizontal distances between the stakes or between any stake and a' known 'depth to which the ditch must be cut. Also, errors in computation may become involved. I

If the person or concern employed to dig the ditch and install the sewer pipe connection between the residence or building and the sewer main were equipped with a surveyors transit capable of having its telescope vertically adjusted, the telescope after initially having been levelled could thereafter be accurately depressed or elevated so as to sight parallel to the required grade. However, surveyors transits capable of such vertical adjustment are relatively expensive. and for this reason most persons or concerns engaged in this type of work do not purchase them but instead employ only builders levels.

An object of the present invention is to provide a method and apparatus by which a person or concern equipped witha conventional builders level can accurately and easily lay out on uneven terrain stakes on the course of the proposed ditch anddetermine at the locations of the stakes the depth to which the ditch must be dug to main- United States Patent 7 a 'zazas sa a -t ed Feb. 123, 195

ICE

a portion of the apparatus shown in FIG. 1 on an enlarged or exaggerated scale wherein the apparatus is used in sighting the downgrade; V V

FIG. 3 is a similar view wherein theapparatus is used for sighting upgrade;

FIG. 4 is a perspective view of a prism shown in a highly exaggerated form and which forms'a 'part of the present apparatus;

FIG. 5 is a view in. front elevation of' a target pole which forms a part ofthe apparatus shown in FIG. 1;

FIG. 6 is a vertical section through the target pole taken substantially upon the line 66 upon FIG. '5 in the direction indicated; and a FIG. 7 is a horizontal section taken substantially upon the .line 7 7 upon FIG. 6 in thedirectionindicated; I

FlG.'8-is a view in front elevation of a portion of the target pole shown in FIG. 5 and illustrating the manner in which the targets may be adjusted in accordance with the present invention. 1 I 1 Referring to the accompanying drawings wherein similar reference characters designate similar parts throughout,.l0 may indicate the sewerpipe connection that leads 7 directly into a sewer main. The depth of this connection The location at which the builders level is'set up may be either at the sewer outlet from the residence or the builders'level may be set up at some intermediate station between the sewer outlet from theresidence and the sewer connection lilo As above explained, a certain predetermined slope or fallmust be 'maintained'in the sewer pipe connection leading from the residence to the sewer connection ltl. This slope or fall frequently isrequired to be' fi per foot although this slope may be varied. If the slope is to be A" per foot a transparent prism 14 is provided. This prism may be formed of optical glass or other transparent material. In FIGS. 2, 3, and 4 the thickness of this prism is illustrated in a highly exaggerated manner. The prism 14 may be in the form of a very thin section of optical glass disposed within a frame 15 having indicators at the top and bottom thereof to indicate when. the prism is right-side up or upside down. This prism and its frame are receivable either in a right-sideup or upside down position in a suitable holder 16 that is attached to the forward end of the telescope of the level. The prism is so constructed that it will retract light in the proportion of the proposed grade or fall of the ditch. In other words, if the required grade or fall of the ditch is M1,, 'per foot, then the prism is so ground that it will retract light passing therethrough in the same proportion. In the position shown in FIG. 1, the builders level is located upgrade from the sewer connection 10 and is shown as sighting downgrade therefrom. The prism 14 is consequently applied in an upright position wherein it retracts the light so that as viewed through the telescope 13 the level line to be depressed along the line S which line S is perfectly parallel to the grade of the proposed ditch.

A target pole 17 is provided having two distinguishable targets 18 and 19. These targets are independently adjustable along the length of the pole and areso arranged that one target can pass the other without interference. For this purpose the forward and rear sides of the target pole may be grooved as indicated at 20 to provide tracks or ways for flanges 21 on the front and backs of the targets. Spring-actuated leversr22 having friction pads 23 may be pivotally mounted onthe targets and when the levers 22 are released these friction pads serve to hold the targets in their adjusted positions. On depressing the levers 22 the friction pads 23 are caused to disengage the target pole'and permit of free adjustment of each target.

The target 18 is located at the juncture of two flexible scales 24 and 25, the scale 24 reading upwardly from the target 18 and the scale 25 reading downwardly therefrom. Rollers or pulleys 26 and 27 are rotatably mounted on the target pole near the top and bottom thereof and the flexible scales 24 and 25; are trainedover these rollers and are connected, such as by a tension spring 28. The forward portions of the scales 24 and 25 are slidable in a groove 29 on the forward side of .the target pole and the portions of the scales that are connectedzby the tension spring 28 are movable in a groove 31) on the rear side of the target pole. As the two scales are riveted or otherwise secured to the target 18 they are-vertically movable on the target pole thereby. They are readable against the target 19.

With the apparatus as above described set up as shown in FIG. 1, the target pole is positioned in the bottom of the hole 11 or at the known depth that the ditch must reach to make the connection to the sewer connection 10.

By sighting through the telescope '13 over the horizontal cross-hair therein and through the prism 14 the target 19 is adjusted to a position determined by the sight line S. For a given situation this position assumed by the target 19 is retained or preserved for all further steps. Proceeding toward the level the target pole may then be positioned on an elevation 31. Thelocation of the target pole on this elevation is determined in reference-to the vertical cross-hair in the telescope 13 so as to be on the course parallel to the proposed: ditch. A stake 32 is then driven and the target pole positioned on top of this stake with the bottom of the target pole resting on the stake. By sighting through the telescope the target 18 is then adjusted on the target pole until it coincides with the line of sight S. This, in the condition shown, would require the target 18 to assume a position on the target pole below the target 19. The

distance between targets 18 and 19 is directly readable on the scale 24 against the target 19 and this distance represents the depth to which the earth must be removed below the top of stake 32 for the required grade at this point or station. The depth to which the earth must be excavated at this location may be written on the side of the stake or on a lath driven close to the stake. From this station similar stakes may be located and driven at 33, 34, and 35. If, in the line of the proposed ditch there is a depression as indicated at 36, a stake may be driven in this depression and a reading taken in the same manner wherein the distance d measured between the targets by the scale 24 represents the distance d that must be excavated from the bottom of the depression 36 to the line of proposed grade.

If the bottom of the depression 36 should have been so deep that it was below the line of the proposed grade, this would cause the adjustment of the target 18 to assume a position above the target 19 when it was lined up with the sight line S at this location. The distance be- 4 tween the targets under these circumstances would be to raise the depression to the line of proposed grade.

If the level is located at an intermediate point between the residence and the sewer connection 10 after the stakes 32, 33, 34, and 35 have been located, driven, and the depths at these locations noted, the telescope 13 on the level may be turned around so as to look upgrade rather than downgrade as in FIG. 1. Under these circumstances, the prism 14 is reversed so that instead of depressing the level line L to thefline of sight S, it will elevate the level line L to, a line of sight that is above level proportional to the slope of the proposed grade. In setting further stakes upgrade from the level the position of the target 19 is not disturbed. But the target 18 is adjusted to be brought into alignment with the line of sight S and the spacing between the targets is read directly on either of the scales Z4 and at the various stations and noted on or adjacent the stakes.

If the depth of pipe 10 is known from a previous survey a stake illustrated in dotted lines at 37 is driven directly above the end of the pipe 10 and the cut or depth marked on the stake or adjacent to it. The target pole is then placed on the stake 37 and target 18 is first adjusted to the sight line S and locked in place. Target 19 is then raised along scale 24 to set at the reading that was previously marked on or adjacent stake 37. Target 19 is then locked and assumes the stationary position relative'to which target 18 is adjusted at the various locations along the length of the proposed ditch.

From the above-described method and apparatus it will be appreciated that the conventional, inexpensive builders level can continue to be employed, and that by the mere addition of the prism 14 and the supplying of a target pole with two independently adjustable targets, that the depth to which earth must be excavated to maintain the proposed grade can be easily and quickly ascertained, eliminating computation errors. Furthermore, it is unnecessary to accurately measure the horizontal spacing between stakes or the distance between the level and any selected stake. The stakes maybe driven more or less at random along the source of the proposed ditch, and wherever they are located the depth to which the ditch must be dug to maintain the grade can be instantly read on scale 24 or scale 25 as being the distance between the two targets.

The equipment above-described may also be used not only in laying out graded ditches, but for purposes of land levelling wherein the prism 14 is used for maintaining a slope for drainage. It may also be used without the use of prism 14 for determining absolute level for irrigation purposes by following the same procedure as above outlined for sewer ditches.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. Apparatus for establishing a grade comprising, in combination, a builders level having a tripod and a crosshaired telescope, a prism applicable to the telescope in either upright or upside down positions, means .on the prism for-indicating whether it is applied in upright or upside down position, said prism being of a character to retract a level ray of light through the telescope-upwardly or downwardly depending upon its applied position an amount equal to the amount of the proposed grade, and a target pole having two targets adjustable vertically thereon independently of each other, and scales on the target'pole progressing upwardly anddownwardly from one target and movable thereby, which scales are readable against the other target.

2. The method of ditching to a predetermined grade which includes setting up a builders level on the proposed line of the ditch, applying to the telescope of the 6 level a prism which will vertically alter the line of sight References Cited by the Examiner in accordance with the grade,-setting a target pole with UNITED STATES PATENTS its bottom on a known elevation on the grade, setting a t target on the target pole at the level as viewed through V i g f the telescope and prism, setting stakes along the line of 5 984138 2/11 Harrison 33 70 the ditch from observations made through the telescope, 2 414777 1/47 Thomas X setting a second target on the target pole at thetlocation 13:72 7 /55 Henderson of each stake from observations made through the telei scope and prism, measuring the distance between the tan FOREIGN PATENTS gets, and noting the distance between the targets at the 10 ,8 Austriastakes. ISAAC LISANN, Primary Examiner. 

1. APPARATUS FOR ESTABLISHING A GRADE COMPRISING, IN COMBINATION, A BUILDER''S LEVEL HAVING A TRIPOD AND A CROSSHAIRED TELESCOPE, A PRISM APPLICABLE TO THE TELESCOPE IN EITHER UPRIGHT OR UPSIDE DOWN POSITIONS, MEANS ON THE PRISM FOR INDICATING WHETHER IT IS APPLIED IN UPRIGHT OR UPSIDE DOWN POSITION, SAID PRISM BEING OF A CHARACTER TO REFRACT A LEVEL RAY OF LIGHT THROUGH THE TELESCOPE UPWARDLY OR DOWNWARDLY DEPENDING UPON ITS APPLIED POSITION AN AMOUNT EQUAL TO THE AMOUNT OF THE PROPOSED GRADE, AND A TARGET POLE HAVING TWO TARGETS ADJUSTABLE VERTICALLY THEREON INDEPENDENTLY OF EACH OTHER, AND SCALES ON THE TARGET POLE PROGRESSING UPWARDLY AND DOWNWARDLY FROM ONE TARGET AND MOVABLE THEREBY, WHICH SCALES ARE READABLE AGAINST THE OTHER TARGET. 